It is now commonplace in, for example, production machinery for all of the actuating cylinders to be controlled by respective directional control valves that are usually mounted on one and the same ‘valve island’. The valves in the valve islands are usually controlled by solenoids that receive electrical signals to actuate the associated valve. The valve islands are thus connected to a pneumatic line that supplies pressurized gas, an electrical line to provide power for the solenoids and an electrical communication line to control the operation of the valve island. Such valve islands have the advantage of compactness but each one requires the connection of electrical, communication and pneumatic lines. Therefore, production machinery having several valve islands will require a relatively complex network of supply lines for their operation, which can be difficult to install and expensive for the end-user.
More recently valve islands have been constructed to make use of wireless communication technology to control the operation of the solenoids on the valve island. Thus, these valve islands do not require a communication line. However, these valve islands still require a network of pneumatic and electrical power lines and thus the support network for a plurality of valve islands is still complex.